index(S) takes a string, S, and returns a dictionary, indexed by the lower case letters a...z, where the value represents the number of occurrances of that letter in S. Example: >>> index('The rain in Spain') {'t': 1, 'h': 1, 'e': 1, 'r': 1, 'a': 2, 'i': 3, 'n': 3, 's': 1, 'p': 1}

def index(S):

Please help using return not print